1 . Chicks require attentive parents for survival. Both parents feed the chick regurgitated food. Adults recognize and feed only their own chicks. Parents are able to identify their young by their chick's distinctive call.

2. Male emperor penguins exhibit a feature unique among penguins. If the chick hatches before the female returns, the male, despite his fasting, is able to produce and secrete a curdlike substance from his esophagus to feed the chick allowing for survival and growth for up to two weeks.

A parent penguin feeds its chick regurgitated food.

3. Parents brood chicks (keep them warm) by covering them with their brood patch.

4. In some species, partially grown chicks gather in groups called creches. (Creche is a French word for crib.).

a. Creches provide some protection from predators and the elements.

b. Creches were once thought to be functional nurseries with adults providing protection and communal care. This has proven not to be the case since there is no feeding other than by parents.

c. Temperate or subtropical crested penguins, like the macaroni or erect-crested, and penguins that nest in burrows, like the fairy or Humboldt, do not form creches.

1. When in the water, penguins may be eaten by leopard seals, fur seals, sea lions, sharks, or killer whales.

2. On land, foxes, snakes, and introduced predators such as feral dogs, cats, and stoats (members of the weasel family) prey on eggs and chicks of some penguin species, including the yellow-eyed and Galapagos penguins.

3. Antarctic and subantarctic eggs and chicks are susceptible to predatory birds such as antarctic skuas, sheathbills, and giant petrels (del Hoyo, et al., 1992). These predators may prey on chicks that have strayed from the protection of the creche or are sickly and too weak to defend themselves.

a. Skuas may work in pairs to obtain their prey. One bird distracts the penguin on the nest, and the other swoops in to steal the egg or chick.

1 . Historians believe that indigenous peoples have hunted some species of penguins and taken eggs for centuries.

2. Mass exploitation occurred when early explorers, sealers, whalers, and fishermen turned to penguin colonies as sources of fresh meat and eggs. Sometimes more than 300,000 eggs were taken in annual harvests from one African island. Explorers were known to kill and salt 3,000 penguins in a day for voyage provisions. Penguins were easy prey because of their inability to fly and their seeming lack of fear of humans. Although egg-collecting was banned in 1969, illegal harvesting continues today.

3. During much of the 19th century, and into the 20th, penguin skins were used to make caps, slippers, and purses. Feathers were used for clothing decorations and as mattress stuffing. Inhabitants of the remote island grouping in the South Atlantic, Tristan da Cunha, still depend on penguins for eggs, feathers, oil, and skins.

4. The extraction of oil from penguins' fat layers became economically important in the 1800s and early 1900s. Oil was used for lighting, tanning leather, and fuel. In the Falkland Islands alone, an estimated 2.5 million penguins were killed within a 16-year timespan. The oil industry came to a halt in 1918 due to protests by the general public and because of cheaper and better quality chemical products.

5. Humboldt penguin guano has great commercial value as a nitrogen-rich fertilizer. Although the Incas used penguin and seabird guano to improve their crops as far back as 500 B.C., they carefully managed the resource by extracting it at a slower rate than it was being produced. Guano became a major product of international trade in the 1800s, and in the early 1900s the deposits were in danger of being depleted. Guano harvesting is better managed today, but overexploitation of this commodity is a serious threat to the Humboldt population.

6. In some places, such as islands in the southern Indian Ocean, fishermen still use penguin meat for bait.

7. Human competition for food sources can affect penguin populations. Overfishing of anchovetta (a small fish), the primary food source of the Humboldt penguin, has contributed to their population decline.

8. The introduction of predators has had devastating effects in some areas. Rats, dogs, pigs, and ferrets have been known to prey on chicks, eggs, and even adult penguins. Introduced herbivores, such as sheep and rabbits, cause serious deterioration of habitat.

9. Colonies of penguins have been affected by building activities and road construction. One colony of king penguins at Iles Crozet (a small group of islands in the Indian Ocean) was completely destroyed. A nearby area was cleared, and fortunately, the penguins recolonized.

10. Trash in the ocean can affect seabirds. Penguins have been known to ingest plastic or become tangled in debris, causing injury and death.

11. Oil spills affect penguins.

a. Oil fouls their feathers, reducing the waterproofing and insulating properties of their plumage. The birds become susceptible to hypothermia (chilling).

b. Penguins also ingest the oil while trying to preen, poisoning them and causing internal organ damage. c. Oil spills are a continued threat. In June 1994, an estimated 40,000 African penguins were affected by an oil spill off South Africa's Cape peninsula. More than 2,400 tons of fuel oil was spilled. The disaster occurred during the penguins' breeding season, affecting the survival of chicks and unhatched eggs. The long-term success of emergency clean-up efforts probably will not be determined for several years.

Enthusiastic sightseers must be careful not to interfere with normal penguin activity.

13. Activity that may seem harmless, such as aircraft flying over penguin colonies, may cause panic and stampedes, resulting in injuries and easy predation.

14. The popularity of "ecotourism" is increasing with cruise ships frequenting antarctic waters. Enthusiastic sightseers must be careful not to interfere with normal penguin activity by staying back and keeping noise levels down.

15. Penguins may be indirectly affected by past hunting of whales. The increase of some penguin species over the last 30 years may be attributed to the greater availability of krill following the reduction of some antarctic whale populations. However, the commercial value of krill may encourage large-scale harvesting of this resource in south polar waters, which would impact penguins and other marine animals that rely upon krill as a food source.

El Nino is a natural phenomenon that involves a change in wind and ocean current patterns, which warms surface temperatures and reduces the upwelling of nutrient-rich water. A decrease in nutrients affects plankton, krill, and small fishes, which comprise the food supply for marine animals. The penguin species most affected are the Humboldt and Galapagos penguins. The 1982 El Nino caused a 65% depletion of the Humboldt population off the coast of Peru (Collar and Andrew, 1988). Up to 77% of the Galipagos population was wiped out, leaving only 463 total birds. A slow recovery began in 1985.

1. Like most seabirds, penguins tend to be long-lived. They may take three to eight years to reach sexual maturity.

2. With some of the smaller species, breeding may begin at three or four years, but most larger species are not accomplished breeders until much later. On average, breeding does not begin until the fifth year, and a few males do not breed until the eighth year.

a. Most species have an annual breeding season - spring through summer.

b. The king penguin has the longest breeding cycle of all the penguin species, lasting 14 to 16 months. A female king penguin may produce a chick twice in every three breeding seasons.

c. Emperor penguins breed annually during the antarctic winter, June through August.

(1) During the emperor breeding season, air temperature may drop to -60Ãƒâ€šÃ‚Â°C (-76Ãƒâ€šÃ‚Â°F) and winds may reach speeds up to 200 kph (124 mph).

(2) For most of the winter, antarctic penguins live in an environment of darkness or half-light. Why emperors breed during the harshest season of the year is unknown, but some scientists speculate that when the chicks become independent five months later (in January or February, the antarctic summer), environmental conditions are more favorable for the young birds.

d. The fairy penguin breeds throughout the year and has the shortest breeding cycle, about 50 days.

e. Some of the temperate penguins, like the Humboldt and the African, tend to nest throughout the year.

a. Courtship varies among the species. It generally begins with both visual and auditory displays. In many species, males display first to establish a nest site and then to attract a mate.

b. Most penguin species are monogamous (one male breeds with one female during a mating season) ; however, research has shown that some females may have one to three partners in one season and some males may have one or two partners.

c. Mate selection is up to the female, and it is the females that compete for the males.

e. When a female selects a different mate it is usually because her mate from the previous season fails to return to the nesting area. Another reason may be mistiming in returning to the nesting area. If they arrive at different times and miss each other, one or the other penguin may obtain a new mate.

c. Some scientists believe that penguins build up numbers in a single rookery rather than colonize new areas because mature birds return to the rookery where they hatched when it is time to breed. Some penguin rookeries number millions of birds.

a. Emperor penguins form colonies around the shoreline of the antarctic continent and adjacent islands. They prefer sites on a fairly level surface of ice in areas sheltered from wind, with easy access to feeding areas.

b. King penguins nest and breed on subantarctic and antarctic islands. They prefer beaches and valleys of level ground or gentle slopes, free of snow and ice, and accessible to the se.

d. Gentoo penguin colonies can be inland or coastal on antarctic and subantarctic islands and peninsulas. They tend to breed on ice-free ground on beaches, in valleys, on inland hills, and on cliff tops.

e. Chinstrap penguins nest on fairly steep slopes.

f. Fiordland crested penguins nest in a wet, coastal rain forest habitat, under bushes, between tree roots, in holes, or in caves.

g. Galapagos penguins nest in volcanic caves or cracks in rock.

Some penguins, like these gentoos, construct nests of small stones.

h. The temperate penguins and the fairy penguin nest underground in burrows. These species breed in areas where the climate can range from tropical to subantarctic. Underground burrows provide an environment with a relatively constant temperature (about 25Ãƒâ€šÃ‚Â° to 29Ãƒâ€šÃ‚Â°C, or 70Ãƒâ€šÃ‚Â° to 84Ãƒâ€šÃ‚Â°F) for the eggs and chicks.

b. Chinstrap penguins usually construct nests with perimeters of eight to ten stones, just enough to prevent eggs from rolling away.

c. Gentoo penguins use nesting materials ranging from pebbles and molted feathers in Antarctica to vegetation on subantarctic islands. One medium-sized gentoo nest was composed of 1,700 pebbles and 70 molled tail feathers.

d. Emperor and king penguins build no nests. They stand upright while incubating a single egg on the tops of their feet under a loose fold of abdominal skin. Under this loose fold is a featherless patch of skin called a broodpatch, which occurs in all incubating birds. The brood patch contains numerous blood vessels, that, when engorged with blood, transfer body heat to the eggs.

3. A nest of eggs is called a clutch, and with the exception of emperor and king penguins, clutches usually contain two eggs. (Emperor and king penguins lay a single egg. ) A clutch with more than one egg presents a better chance of at least one chick surviving.

a. In the Eudyptuia, Spheniscus, and Pygoscelis genera, the first-laid egg is generally larger than the second, and usually hatches first (except in the chin. Usually the first chick to hatch has the survival advantage since it will already have fed and will be larger by the time the second egg hatches. The second, usually smaller, chick cannot compete with the larger chick for food and usually perishes.

b. In the Eudyptes genus, the second-laid egg and subsequent chick is usually the larger of the two. The second chick usually is the survivor. Researchers have yet to find an adequate theoretical explanation for this reversed pattern.

c. The chinstrap and yellow-eyed species usually lay two eggs. Parents typically raise both chicks, which are nearly equal in size.